Q18 - In an island nature preserve,

[Laura Damone]

Question Type:
Explain a Result

Stimulus Breakdown:
No argument here, so we just need the facts. There are three locations for Common Eider nests: woody vegetation, wooden boxes, and open grasslands. Some Common Eiders lay their eggs in other Common Eider nests, probably to make the eggs maximally safe from predation. One would expect the nests concealed in woody vegetation to be the most commonly selected for females looking to lay eggs in existing nests, but actually the wooden box nests are the most commonly selected.

Answer Anticipation:
Why are some birds laying eggs in other bird's nests? To keep the eggs safe from things that want to eat them. So, in order to explain why the wooden box nests are more appealing than the woody vegetation nests, we can predict something that will show the box nests to be safer from predation.

Correct answer:
B

Answer choice analysis:
(A) Right out of the gate, A seems wrong because of the word "some." Remember, on the LSAT, "some" only necessarily implies "one," and the chance of one example explaining anything is pretty unlikely. Reading on, we find some irrelevant details. Who cares if birds use another bird's nest one year then build their own in subsequent years? That doesn't explain anything about the nest choice.

(B) Hmm…if this were the case, would it explain why the wooden box nests are being chosen at higher rates than the woody vegetation nests? Absolutely. If they can't detect them, they can't lay eggs in them. It doesn't match our prediction, but it works nonetheless.

(C) Speaking of deterrents, "sometimes" in this answer is a deterrent for us! Reading on, this answer doesn't describe anything that would contribute to the woody veg. vs. wooden box choice. We need there to be some difference between the two nest sites to explain the choice and this answer describes something that is not site-specific.

(D) Altered by humans? Who cares? And like C, this doesn't offer a site-specific difference that could impact the bird's choice.

(E) Like C and D, E also doesn't present a site-specific difference. The presence of predators generally doesn't explain a choice of wooden box nests over woody veg. nests.

Takeaway/Pattern:
Explain a Result questions are so often about "why was it X instead of Y." In these cases, something that's true for both X and Y won't explain why it went one way instead of the other, so rule out answers that don't address some sort of difference (A, C, D and E). And if you make a prediction for an Explain a Result question, don't be so wedded to your prephrase that you fail to see when another answer would work in a different way.

#officialexplanation

[DavidP715]

Can you elaborate more on B? Because its more difficult to detect it therefore makes sense for them to choose them?